Donald Trump has warned Ted Cruz that he would ‘spill the beans’ on Heidi Cruz and said the Texas senator should ‘be careful’.

Trump was ignited by a picture of his wife, Melania Trump, that was used during the U.S. Presidential nominations.

In a tweet on Tuesday he says, "Lyin' Ted Cruz just used a picture of Melania from a G.Q. shoot in his ad. Be careful, Lyin' Ted, or I will spill the beans on your wife!"

This came about 10 minutes after he tweeted a similar message but deleted it.

Foreign media says that Trump was referring to a Facebook advertisement targeted to Mormons that depicts Melania posing nude. That ad was produced by an anti-Trump super PAC, Make America Awesome, which has no known connection to the Cruz campaign.

However, taking the feud to a whole new level Cruz replied saying that the advert was not his and if Trump pulls his wife into it, then he is a ‘coward’.

"Pic of your wife not from us. Donald, if you try to attack Heidi, you're more of a coward than I thought. #classless,” he tweeted.